Refrigerating system



Jan. 21, 1936. I s" U HT 2,028,565

REFRIGERATING SYSTEM Filed March 18, 193;

ILKVA 7 INVENTOR 4 SIEGFRIED HUPPH/CHZ J7 ATTORNEY Patented Jan. 21, 1936 UNITED STATES PATENT OFFICE 12 Claims.

This invention relates to improvements in refrigerating systems and has for an object the provision of a plurality of refrigerating units operating from a condenser which is, in turn, refrigerated by any means such as a compression system, an absorption system, ice and salt, etc.

In multiple installations such as apartment houses, etc., it is very expensive to buy a complete unit such as is on the market today for each apartment. By the use of a main refrigerating unit and the system disclosed in this invention, the cost of such installations may be substantially reduced.

An auxiliary condenser made of a coil of pipe, preferably in the form of an inverted frustrum of a cone, comprises the side wall of a chamber adapted to be refrigerated by the large unit referred to above. Gaseous refrigerant passing into this coil has its heat removed by the cold in the chamber, liquefies and settles-into a receiver which is connected to the bottom of the'con denser.

Liquid refrigerant is led from this receiver to a plurality of evaporators located in boxes in the various apartments throughout the building, and a return pipe leads the gaseous refrigerant back to the auxiliary condenser, forming a separate closed system.

Suitable control means are provided for both the main refrigerating unit and for the multiple auxiliary system.

The auxiliary condenser may be made in a variety of forms other than described above and the term chamber may be taken to mean any conduit or vessel in heat exchange relation to the auxiliary condenser.

The auxiliary condenser and its allied evaporators contain no lubricants, absorbents or adsorbents which might tend to retard the heat transfer by insulating the interiors of the pipes.

Another object of the invention is to superimpose a stream or spray of liquid refrigerant on the stream of gas passing through the auxiliary condenser in order to speed up the heat transfer and therefore accomplish faster liquefaction of the gas. This may be accomplished .by any suitable means; for example, a centrifugal pump may be used inconjunction with a jet arrangement wherein the spray of liquid refrigerant through the jet will cause the gaseous refrigerant to move therethrough at a greater rate of speed, thereby efl'ecting faster condensation. This centrifugal pump may be driven by a motor and controlled by the pressure of the gaseous.

refrigerant in the return pipe of the system.

Still another object of the invention is to provide a multiple auxiliary refrigerating system which will operate in a cycle or cycles independent in respect to the cycling of the main source of refrigeration. In cases where the relay condenser is refrigerated by a refrigerating machine the operation of the latter may be controlled manostatically or thermostatically, and it is sometimes preferable to have it make comparatively long runs, and sometimes preferable to have it make comparatively short runs.

Another object of the invention is to have the liquid line surrounded by the gas line thereby effecting a heat exchange between the liquid and gaseous refrigerant and also insulating the liquid refrigerant from the heat of the outside air.

Other objects will be apparent to those skilled in the art upon perusal of the specification and appended claims.

Referring to the drawing:-

Figure 1 is a diagrammatic view partly in section showing one embodiment of the invention, wherein the auxiliary condenser is located above the refrigerating units or evaporators;

Figure 2 is a diagrammatic view of a modification of the invention wherein a condenser is located below the cooling units or evaporators;

Figure 3 is a sectional view of an evaporator taken along the line 3-3 of Figure 2.

The relay condenser designated generally by the numeral l0 consists of a vessel, the interior I I of which serves as an evaporator for the main refrigerating system and refrigerant is supplied thereto from the receiver or condenser of the main refrigerating system via expansion valve l2 and the pipe I3. This pipe I3 terminates at a point near the bottom of the chamber ll, so that the refrigerant entering the chamber will agitate any refrigerant already in the chamber. The slanting walls I! of the chamber are formed from a coil of pipe wound in the form of a frustrum of a cone. This coil serves as a condenser for the auxiliary system.

A bottom closure l5, preferably in the form of a dome and a top closure l6, also domeshaped, are secured to the slanting walls I4 in any suitable manner to form the fluid-tight chamber H. A suction pipe I! is provided for removal of gaseous refrigerant from chamber II.

To facilitate a circulation of liquid refrigerant in the chamber H, a conical shaped bafile [8 supported on the upper'wall l6 by brackets l9 and 20 is provided. Suitable control means for the main refrigerating system may be provided.

A plurality of evaporators 2|, 22 are connected at a point above the evaporators 2| and 22. In c with the gas line 23, which extends to the jet 24 and connects thereto at the point indicated by the numeral 25. This Jet is connected to the upper end of the coil which forms the wall H. The other end of this coil terminates in the receiver 25 and gaseous refrigerant passing from the evaporators 2| and/or 22 via pipe 23, condenses in the coils 4 and liquid refrigerant settles into receiver 25. This condensation is accelerated by superimposing on the gas stream a jet of liquid refrigerant which speeds up the passage of refrigerant through the coil l4 and at the same time overcomes friction of the gases against the walls of the pipe 23. This is accomplished in the following manner:

Liquid refrigerant from the receiver 25 is supplied via the pipe 21 to a centrifugal pump 23. A motor 29, drives the centrifugal pump 23 and the liquid refrigerant which goes into the pump via the pipe 21' is carried through the pipe 33 to the nozzle 3| of the jet 24 and the refrigerant leaving the Jet in the form of a spray impels the gaseous refrigerant therethrough.

The pipe 33 also has connected thereto a pipe 32 which supplies liquid refrigerant to the evaporators 2| and 22. The operation of the motor 29 and its pump 23 is controlled by a sylphon bellows 33 which has its interior connected with the interior of the pipe 23. This sylphon 33 operates a switch 34 which is connected to a source of power 35 and the motor 23 via the wires 35, 31, 33.

The arrangement shown in Figure 1 covers a system wherein the relay condenser is located many cases it is desirable to have the auxiliary condenser located at a point below the evaporators. Such an arrangement is shown in Figure 2 wherein the auxiliary condenser II has its interior chamber connected via the pipe H to a compressor 39 of a refrigerating system. The gas after being compressed passes via the pipe 43 into a condenser 4| and the gases liquefied therein settle into a receiver 42 and pass therefrom via the pipe 43, the expansion valve l2 and the pipe l3 into the chamber Any suitable method for driving and controlling the operation of the compressor may be provided.

A plurality of evaporators, 44, 45, 43 are provided and these are supplied with a liquid refrigerant from a tank 41 located at a point above the evaporators. The tank 41 is preferably surrounded by insulating material 43. A float valve 49 is provided in the tank 41 to keep a predetermined liquid level therein. Liquid is supplied to the tank 41 via the pipe 53 in a manner which will hereinafter be described.

This pump 53 is surrounded by the suction pipe 5| which not only insulates it from the outside air but eflectsa heat exchange between gaseous refrigerant in the pipe 53 and liquid refrigerant in the pipe 5|. This suction pipe is connected to the evaporators 44, 45, 43 by the pipes 52, 53 and 54, respectively. The pipe 55 connected to the pipe 5| has mounted thereon the sylphon 33 which operates the switch 34, thereby controlling the operation of the motor 23 which drives the centrifugal pump 23 as above described.

The coil of pipe 55 is wound in heat exchange relation to the wall H of the relay condenser and has therein a similar coil of pipe 51. Gaseous refrigerant from the pipe 55 is carried through the coil 55 and upon passing therethrough is led by the pipe 53 to the outer portion of the jet 24. Liquid refrigerant is carried from the receiver 25 via pipe 21 to centrifugal pump 23 and pipe 59 to the spray nozzle 3| of the jet 24. The pipe59 has a branch connection 50 which connects to the coil 51 which is within the coil and passes via the pipe 55, the pipe 53 and the floatyalve 49 to the receiver 41.

The tank 41 is connected to the suction pipe 50 by pipe 32 which contains a check valve 5|.

This check valve allows gas or vapor to pass from the tank 41 when liquid is passing in.

The evaporators 2|, 22, Figure l, are located in suitable insulated boxes and the system is charged with a suitable refrigerant. a The chamber II is refrigerated by any suitable method such as a high side unit as shown at 39, 4|, 42 in Figure 2, and gaseous refrigerant from the evaporators 2|, 22 tending to seek the coldest part of the system flows via the pipe 23 into the auxiliary condenser H which forms the wall of the chamber The pressure in the pipe (and incidentally the evaporators 2|, 22) causes the sylphon 33 to close the switch 34 and thereby complete the circuit between the motor 29 and the source of power 35. The pump 23 is driven by the motor 29 and takes liquid refrigerant from the receiver 23 via the pipe 21 and, via the pipe 33, forces the liquid "through the nozzle 3| of the jet 24.

- The liquid leaving the nozzle 3| in a fine spray and at a high velocity mixes with and impels the gaseous refrigerant into the condenser H at a high rate of speed thereby speeding up the rate of heat exchange between the cold chamber and the warmer gaseous refrigerant, which liquefies and settles into the receiver 23.

The evaporators 2| and 22 are provided with suitable expansion valves (not shown) and receive liquid refrigerant from the receiver 23 via the pipe 21, the pump body 23 andthe pipe 32.

The operation of the system continues until all evaporators connected thereto are reduced to the same temperature and the corresponding pressure in the return pipe 32 allows the sylphon 33 to open the switch whereupon the motor 23 and pump 23 cease to operate.

In this system only one control is necessary on a multiple installation as all of the evaporators in the system are reduced ,to a predetermined temperature and the rates of refrigeration of the various evaporators are inherently accelerated.

For example, when the system starts operating the warmest evaporator boils at a faster rate than the colder ones, and as the operation continues the rate of boiling gradually decreases as the temperature reduces and finally when they will arrive at the predetermined temperature level, the operation ceases.

If a higher temperature is desired in one or more of evaporators of a system of this kind. a

' suitable automatic valve may be placed in the return pipe of the evaporator in which the higher temperature is desired. Then when the temperature for which the automatic valve is set is wall l4 tends to cause bubbles that form thereon to rise through the liquid instead of sliding along the surface.

In the system outlined in Figure 2, the operation is the same as described for Figure 1 except, that in this case the evaporators 44, 45, 46 are located above the level of the auxiliary condenser. An auxiliary receiver 41 is provided above the level of the evaporators, and a liquid line runs directly to this auxiliary receiver.

A second liquid line 64 supplies liquid refrigerant to the evaporators from the auxiliary receiver.

Gaseous refrigerant is led from the evaporators 44, 45, 46, via the pipe 5|, the pipe 55, the coil 56, the pipe 58 and the jet 24 to the condenser H.

The pipe 5| surrounds a part of the length of the liquid line 50 effecting a heat exchange between liquid and gaseous refrigerant and at the same time insulating the line 50 from the temperature of the outside air.

The coil 56 surrounds a portion 51 of the liquid line and is in heat exchange relation to the outside of the condenser coil l4.

The float valve 49 regulates the level of liquid in the auxiliary receiver 41 and the check valve 6| allows gas to escape into the return line 5| via the pipe 62 when the receiver 41 is being filled. A

The check valve 6| is of suflicient weight or balance to prevent the loss of refrigeration by boiling in the receiver during the operation of the system.

The evaporators are each provided with a float valve having a fioat 69 mounted on a pivot pin TI and so arranged when a predetermined level of liquid enters the evaporator, the needle valve 10 closes. A suction pipe 53 terminates in the evaporator above the liquid level. The liquid level is indicated by a dotted line 13.

A motor 6'! driving the compressor 39 of the main refrigerating unit is electrically controlled by a pressurestat 68. The operation of the pressurestat is controlled by means of a small tube 12 which is connected to the crankcase of the compressor (which is of the same pressure as that of the low side l0). As such controls are well known in the art, the operation thereof is not explained in detail. However, this control supplies the motor 61 with current when the pressure in the low side I!) reaches a predetermined high thereby operating the compressor 39. When the pressure in the low side reaches a predetermined low pressure, the control 68 cuts the current off from the motor 61 and the compressor 39 ceases to operate.

I claim:

1. In an auxiliary refrigerating system, a main refrigerated chamber, an auxiliary condenser in heat exchange relation to said chamber, a receiver associated with said condenser, an evaporator adapted to receive liquid refrigerant from said receiver, a return pipe between said evapo- -rator and the condenser, and means responsive to pressure in said return pipe for admixing cold liquid refrigerant with the gaseous refrigerant entering said condenser, thereby accelerating heat transfer between said evaporator and said chamber.

2. In an auxiliary refrigerating system, a main refrigerated chamber, an auxiliary condenser in heat exchange relation to said chamber, a receiver associated with said condenser, an evaporator adapted to receive liquid refrigerant from said receiver, a return pipe between said evaporator and the condenser, and means responsive to pressure in the return pipe and including a jet pump for saturating gaseous refrigerant with cold liquid refrigerant and accelerating the flow of the same through said condenser.

3. In an auxiliary refrigerating system, a main refrigerated chamber, an auxiliary condenser in heat exchange relation to said chamber, a receiver associated with said condenser, an evaporator adapted to receive liquid refrigerant from said receiver, a return pipe between said evaporatorand the condenser whereby gaseous refrigerant may flow from said evaporator to said condenser, means including a jet for accelerating the flow of refrigerant through said condenser, and means actuated by pressure in said return pipe for directly controlling the operating of said first means, thereby indirectly controllin the temperature of said evaporator.

4. In an auxiliary refrigerating system, a main refrigerated chamber, an auxiliary condenser v forming a part of the walls of said chamber, a receiver associated with said condenser, an evaporator adapted to receive liquid refrigerant from said receiver, a return pipe for leading gaseous refrigerant from said evaporator to the condenser, a pump adapted to force cold liquid refrigerant through a nozzle of a jet injector and thereby increase the rate of heat transfer between refrigerant passing into said condenser and said chamber,- a motor for driving said pump, and means actuated by pressure in said return pipe for controlling the operation of said motor.

5. In a refrigerating system, a main refrigerating machine including a cooling unit, a control therefor, an auxiliary condenser comprising a coil forming at least a portion of a wall of said cooling unit, a receiver for receiving liquid refrigerant from said condenser, a plurality of evaporators operatively connected to said receiver, an individual expansion valve for each of said evaporators, a return pipe for leading gaseous refrigerant from the evaporators to said condenser, means for increasing the rate of heat transmission through the wall of said condenser, and a control for said means adapted to operate independent of the operation of said first control.

6. In a refrigerating system, a main refrigerating machine including a cooling unit, a control therefor, an auxiliary condenser in heat exchange relation to said cooling unit, a receiver for replurality of evaporators operatively connected to said receiver, an individual expansion valve for each of said evaporators, a return pipe for leading gaseous refrigerant from the evaporators to said condensers, a jet pump in the return line adjacent the condenser, a pump in the Connection between the receiver and the evaporators and arranged to force liquid refrigerant from said receiver through a nozzle in said jet and thereby increase the speed of refrigerant in the condenser, and a control for the operation of said pump adapted to operate independently in respect to the operation of said first control.

7. In a refrigerating system, a main refrigerating machine including a cooling unit, control therefor, an auxiliary condenser in heat exchange relation to said cooling unit, a receiver for receiving liquid refrigerant from said condenser, a plurality of evaporators operatively connected to said receiver, an individual expansion. valve for each of said evaporators, a return pipe for leading gaseous refrigerant from the evaporators ceiving liquid refrigerant from said condenser, a g

to said condenser, a jet injector in the return line adjacent the condenser, a pump in the connection between the receiver and the evaporators. and arranged to force liquid refrigerant from said receiver through a nozzle in said jet and thereby increase the speed of refrigerant in the condenser, a motor for driving said pump, and control means actuated by pressure in said return pipe for controlling the operation of said motor, said control means operating independently in respect to the operation of said first control.

8; In a system of the characterdescribed, a main refrigerated evaporator, a condenser in contact with said evaporator and/adapted to receive gaseous refrigerant fro ma plurality of auxiliary evaporators, a receiver connected to said condenser adapted to supply liquid. refrigerant to said auxiliary evaporators, and means for superimposing a spray of liquid refrigerant fromthe receiver upon said' gaseous refrigerant entering said condenser for accelerating heat transfer from said auxiliary evaporator to said main evaporator.

9. In a refrigerating system, a refrigerated chamber, an auxiliary condenser in heat exchange relation to said chamber, a receiver associated with said condenser, a plurality of evaporators. an auxiliary receiver, a liquid line leading from said first receiver to said auxiliary receiver, 'a pump between said first receiver and the auxiliary receiver, a second liquid line connecting the auxiliary receiver to said evaporators, and a return pipe leading from said last receiver and said evaporators to said condenser.

10. In'a refrigerating system, a refrigerated chamber, an auxiliary condenser in'heat exchange relation to said chamber, a receiver associated with said condenser, a plurality of evaporators,

an auxiliary receiver located at a point above the level of said evaporators, a liquid line leading from said first receiver to said auxiliary receiver, a pump between said first receiver-and said liquid line, a second liquid line connecting the auxiliary receiver to said evaporators, a return pipe leading from said last receiver and said evaporators to said condenser and a check valve between said last receiver and said return pipe.

12." In a system of the character described, a refrigerated chamber, an auxiliary condenser in heat exchange relation to said chamber, a receiver associated with said condenser, a plurality of evaporators, an auxiliary receiver located at a point above the level of said evaporators, a liquid line having a pump therein and adapted to carry liquid refrigerant from said first receiver to said auxiliary receiver, a valve for controlling the level of refrigerant in the auxiliary receiver, a second liquid line connecting said auxiliary receiver to said evaporators, a return pipe leading from said last receiver and said evaporators to said condenser, and a check valve between said last receiver and said return pipe.

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